var Toast = function(config){

    this.context = config.context==null?$('body'):config.context;//上下文

    this.message = config.message;//显示内容

    this.time = config.time==null?3000:config.time;//持续时间

    this.left = config.left;//距容器左边的距离

    this.top = config.top;//距容器上方的距离

    this.init();

}

var msgEntity;

Toast.prototype = {

//初始化显示的位置内容等

    init : function(){

        $("#toastMessage").remove();

//设置消息体

        var msgDIV = new Array();

        msgDIV.push('<div id="toastMessage">');

        msgDIV.push('<span>'+this.message+'</span>');

        msgDIV.push('</div>');

        msgEntity = $(msgDIV.join('')).appendTo(this.context);

//设置消息样式

        var left = this.left == null ? this.context.width()/2-msgEntity.find('span').width(): this.left;

        var top = this.top == null ? '180px' : this.top;

        msgEntity.css({position:'absolute',top:top,'z-index':'99',left:left,'background-color':'black',color:'white','font-size':'18px',padding:'10px',margin:'10px'});

        msgEntity.hide();

    },

//显示动画

    show :function(){

        msgEntity.fadeIn(this.time/2);

        msgEntity.fadeOut(this.time/2);

    }

}